Hydraulic pump



0d. 28, 1941. c. J. woLFF. V I HYDRAULIC PUMP Filed A'ug. 5, 19:58

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l llllllllllll la .i /f 1 1 INVENTOR. C/ggf J. WOL/"F BY [j ATTORNEYOct. 28, 1941. c. J. wom-fi HYDRAULIC PUMP Filed Aug. 5,' 1958 ssheets-sheet' sv l INVENTOR. (H4/W55 J. WF F Fig. f4

' is conflned to a`n area Patented Oct. 28, 1941 UNITED STATES PATENT`OFFICE 'mrsrum l I i Charles J. Wolfi', San Antonio, -'.l'ex.

This Ainvention relates to the art of pumps and is concernedparticularly with uid pumps of the hydraulic type employed in thepumping of oil or water wells.

Well pumps are commonly located near the well bottom and are operated bymeans of long strings of sucker rods. Such rods frequently .be-

x shut down.' Furthermore, cumbersome mechanical installations arenecessary at the well head in order to actuate the pump rods, and in acrowded eld space is at a premium.

An object of the present invention is to provide lift pump means forwells of any depth automatically operable .through the agency of iiuidpressure supplied at the'well head and conveyed to the pump through thewell tubing.

Another object is to provide a novel hydraulically operable well pumplhaving standing and traveling valves, in which the pressure above thevalves is always the hydrostatic pressure in the well, irrespective ofthe degree of pressure of the operating uid.

' A further object is to provide a fluid pressure operated well pump inwhich the operating uid located above the producing area of the well inwhich the pump is disposed, thereby preventing any extraneous pressurefrom contacting the producing area.

Other objects and advantages will vbe apparent as the descriptionproceeds. v

In the accompanying drawings wherein like characters of referencedesignate like parts throughout the several views:

Figure 1 is a vertical section through a well bore and casing having innear the well bottom, the pump III being shown in elevation.

Figure 2 is an enlarged fragmentaryv vertical -section through the upperend of the pump assembly, and illustrating. the reversible valve' meansin elevation.

Figure 3 is a vertical section, partly in elevation, of the upperportion of the pump.

Fig. 4 is a section similar to Figure 3 but illusthe pump locatedthere;`

trating the intermediate portion, and forming a continuation of Figure3.

Figure 5 is a similar section continuing that of Figure 4 andillustrating the lower end portion of the pump.

Figure 6 is a 6-6 of Figure 3.

Figure 'l is a horizontal section onthe line 1--1 of Figure 3.

horizontal section on the line Figure 8 is a horizontal section on theline 8-8of Figure 3.

Figure 9 is a horizontal section on the line 9-9 oi Figure 3.

Figure 10 is a horizontal section taken on the line IIJ-I0 of Figure 3.

Figure 11 is a horizontal section taken on the line II--II of Figure 4.

Figure 12 is a fragmentary sectional perspective view of a safetymechanism for the valve reversing means.

` Figure 13 is a horizontal section on the line I3I3 of Figure 3.

Figure 14 is a fragmentary perspective of the safety releasing membershown in Figure 12.

Figure 1 illustrates the generalassembly of the pump as positioned in awell; the pump I beingdisposed proximate the bottom of the well borewithin thewell casing 2.' A packer 3 mountedon the lower end of theworking barrel 41 and at its upper end the lower end of the well tubing4. The liquid to be elevated, hereinafter termed the "production, isdischarged from the pump into the casing 2 through diametricallyopposite discharge will be seen that ports I2 whence it passes upthrough the casing to the lead on l at the well head 5. Operating fluidfor the pump, preferably a suitable liquid, is supplied from a surfacereservoir 9 through a pipe 8 to a surface pump 1 from which it is forcedunder the required pressure down through the well tubing I to the pumpI, issuing from the well pump into the casing through the discharge-ports Il! and I I where it mingles with the production and is carriedup to the surface. In those instances in which the operating fluid andthe production are different, separator means (not shown) is associatedwith the lead off 6 whereby the operating duid may be separated out andreturned to the reservoir 9.

With reference to Figures 1, 3, 4, and 5, it

cylindrical head I5 threaded into the lower end of a bushing 16 which isin turn threaded onto the lower end of the well tubing l. The head isprovided with an axial bore 1I closed at its top the pump is secured tothe pump I embodies an upper*v by a bushing 12 mounting a ball checkvalve assembly 13, the purpose of which will be later explained. As bestseen in Figure 6, the head I is formedv with a series of axial passagesI4 disposed radially with respect to the central bore, which passagesopen -at their lower ends into an annular valve chamber I3 in which thereversing valve I8 is mounted for axial reciprocation between an upperseat 68 in the head I5 and a lower seat I1 in a second and lower head23.

The head I5, in the area of the valve I8, is provided with an axialcentral bore 28 registering with the bore 1I, which bore 28 establishescommunication between the valve chamber I3 and an upper chamber 83. Thechamber 83 is open to the exterior of the head I5 by means ofdiametrically opposed ports II extending radially through the head, seeFigure 6. The valve I6 has an integral upstanding stem 84 and a similardepending stem 85. The upper stem has secured thereon an upper closurevalve I8 of smaller diameter than the reversing valve I6 and which isadapted to-engage the seat I8 at the upper end of the bore 28 to cutoil' communication between the chambers I3 and 83.

As shown -best'in Figure '1, the head I5 is further provided with radialbores 2I leading from the bore 28 to the upper ends of a series ofaxially extending passages 22 which open at their lower ends tothe'bottom face of the head. 'I'hese passages 22 are arranged radiallyof thek bore 28, alternating with the passages I4 and somewhat radiallyoutwardly thereof.

The upper-valve stem 84 is guided and centered by means of a circularcross-head 18 workving in the bore 1I. The respective upper and lowerhalves of the cross-head are oppositelybeveled inwardly for cooperationwith a radially disposed spring projected ball detent 68 retained in thehead I5 by the plug 15. The function of this detent istohold thereversing valve I6 and the associatedvvalves on its stem rmly againsttheir seats.

The second and lower cylindrical head 23, detailed in Figures v2, 3, 8,9, and 10 is of the same externalA diameter as the head I5. The upperend portion of this lower head 23 screws upwardly into the recessedlower end of the head I5, and is diametrically reduced to provideaaaoseY passages 24 open to the outer race of the diametrically reducedlower end portion 88 of the head 23 while the lower ends of the passages38 open to the inner face of this portion, as best indicated in Figurel0.

The head 23 supports an inner hollow tubular housing 11 whichA isthreaded at its upper end into the head 23 beneath a stem guide 18. Theupper end portion of this housing is reduced in diameter to provide anannular passage 31 between it and the inner face of the reduced end anannular chamber 25 around its upper end. 50

inlet chamber I3 and an outlet chamber 81 which communicates through thediametrically opposedradial ports I8 to the exterior 'of the head.Thestem 85 has secured thereon a lower cut of! valve 48 adapted to.engage upwardly against I its seat 4I to close off the chamber 81 andthe outlets I8. I

With reference to Figures 2, 3, and 8 it is shown that ythe head 23 isformed with an internal chamber 38 as a lateral enlargement of the bore88 intermediate the lower outlet chamber 81 and the top of the head, andthat this chamber is in communication with the upper ends of a series ofa'xially extending radially 70 disposed passages 38. These passages 33alternate with a series of axially extendng passages 24 arrangedradially outwardly of thepassages 1 3 8 and which Vopen at their upperends. to the annular chamber 25. The

extension 88 of the head. The lower end of the reduced end portion 88 isexternally threaded to take into the upper end of a tubular member 21concentric with andv of larger diameter than the larger lower portion ofthe housing 11 whereby to form a lower continuation of the` annularpassage 31. An outer pump casing 28 having an external diameter equal tothe maximum external diameter of the head 23 is threaded at its v upperend onto the head 23 and at its lower end onto the standing valve barrel41, see Fig- Y ure 5, which mounts in its axial production inlet vconcentric spaced relation, providing an annular passage 31 between thehousing 11 andtube 21, and anannular passage 26 21 and the casing 28. 1

VWith reference tothe lower part of Figure 3 and the upper part ofFigure 4, it is shown that the lower end of the inner tubular housing 11threads onto a reducer 18 into which is threaded the upper end of a tube48 which at its lower end threads into an upper extension. 8'8 of abottom head 38. The lower end of the tube 21 has a sliding t over acorrespondingly reduced portion of the head 38 and abuts an annular stopshoulder 88 on the head. In the assembly of the pump the lower end ofthe tube 21 is welded to the head where it abuts the shoulder 88.

Concentrically nested Within the tube 48 and slidable axially thereof isa tube 53 whose lower end has threaded thereon a stop bushing 81 whichplays axially within the bore 58 provided in the upper extension 88 ofthe head 38. This bore 58 constitutes a' production outlet chamber whichopens to the exterior of the pump casing 28 through a pair ofdiametrically arranged outlet ports I2 leading through hollow bushings8| (Fig. 11) threaded radially into the body of the4 head and welded attheir outer ends to the casing 28 which is countersunk at the points ofweld.

-These bushings 8| provide the means by'which the head 38 is xed withinand to the pump casing 28.

The head 38 is further provided with a re-h duced lower end extension 82to which is threaded the upper end of a cylinder 3I attached at its.bottom to a bottom pump head 43. The head 43 is axially bored to-receive slidably therethrough the lower hollow tubular plunger 35 whichis attached to a piston 33 and which communicates through the pistonwith a diametrieally smaller upper hollow tubular plunger 34 alsorigidly attached to the piston. Suitable packing 83 is provided in thehead 43 to prevent leakage from the cylinder along the plunger 35,* andsimilar packing 84 is provided in the'head 38 to prevent leakage fromthe cylinder alongthe plunger 34. The

lower end ofthe phinger 35 carries the traveling.A

valve comprising a ball 44 and seat 45, which lower ends of the 75plunger and valve work within l`the working barbetween the tube anglesto the upper pair.

rel 48. The head |03 of the working barrel has a sealing lit against atapered seat 80 located in the upper end of part 41 andas a furtherprecaution against leakage a packing cup 8| is provided as shown inFigure 5. The piston 33 is provided with expansion rings 42. As allproduction contains sand and other foreign material which tends to packin the well casing, and as the production outlet ports |2vare somedist-ance above the packer 3, a'packing cup 82 is fitted to the outerface of the pump casing 26 between it and the well casing 2 immediatelybelow the ports I2, so that the moving stream of production issuing fromthe ports will prevent settling of sand and foreign matter .on the thepacker. Settling and packing of this sand,

or other matter, in the annular space between the wall of the wellcasing 2 and the body of the pump in the distance between the productionports |2 and the upper end of the packer 3 vmight cause diiculty inremoving the packer when the pump and packe assembly is to be removedfrom the well. Since there is no movement` of the liquid in this alreaduring the operation of the pump, any material of greater density thanthe production issuing from the production ports would, unless checked,be free to settle and pack above the packer 3. The motion of theproduction, or operating liquid, above packing 82, will prevent suchpacking ,of sand, or other material', above the production ports l2.

The head 39, see Figure 11, is provided with a radially disposed seriesof axially extending passages 36 which constitute continuations of theannular passage 31 between the housing 11 with its tube 49 and the.tubular member 21. Also,

external channels 29 are formed in the outer face of the head ascontinuations of the annular passage between the tubular member 21 andthe pump casing 28. Ports 32 are provided in the lower end of thecylinder 3l.

The upper plunger 34 has attached to its top a radially slotted head 5|which, in the rising travel of the plunger, contacts anabutment 52 xedlysecured in and to the tube 53. The head 5| is axially bored incommunication with its radial slots so that the production liquid may bedis-V charged from the plunger into the space 95 between the plunger andtube, which space com- A half. vAs the housing 11 is securedto the head23 its follows that the bushing 60 will remain stationary.l In the zoneof the bushing the stem extension 56 is reduced at axially spacedportions 96 and 91 to provide therebetween an annular abutment shoulder51. gaging detents are provided as a means for latching the reversingvalve in either its uppermost or lowermost position. These detentscomprise an upper4 pair of diametrically opposed dogs 58 and a similarlower pair 59 arranged at right Eachdog plays in a radial housing slotprovided therefor in the bushing 60 and is normally urged inwardly bytenlng 11. Each dog is formed intermediate its ends with a reducedshank, 98 and 99respectively, which slidablyengage in axiallyextendingslots 63 provided in a tubular extension 62 attached to theupper end of the tube 53 and moving therewith as the tube is lifted andlowered.

' At its upper end the extension 62 carries an hour glass cam |00 havinga bottom riser 64 and a top riser with an intermediate dwell. The

-top riser 65 acts on the downward movement of the cam to engage behindthe outer end portion of each dog 59 to retract these dogs from the pathof travel of the valve stem abutment shoulder 51, and in order thatduringthe upstroke of the cam its bottom' riser shall not influence thedogs 59 the bottom riser 54 is cut away adjacent each dog 59 to providea planal dwell |l1| as an axial continuation of the dwell |09. In asimilar manner the bottom riser 64 acts on the upward stroke of the camto retract the dogs 58.

In order that the top riser 65 shall not inuence the dogs 58 during thedownstroke of the cam the top riser iscut away adjacent each dog 58 toprovide a planal dwell |62 as an axial continuation of the dwell |00.The yplanal dwells lill and |02 are disposed in relative `right angularrelationship on opposite ends of the cam.

Between `the abutment 52 which is rigidly attached to the tube 53 andthe extension 62 which is also attached to the tube '53 but which isaxially slidable over the valve stem extension 56, the stem extensionhas affixed thereto' an annular abutment 55 which provides a seat forone end of an expansion spring 54 coiled about i abutment 55 alsoprovides a, seat for the lower 4 end of an expansion spring 68 coiledabout the stem extension and bearing at its upper end against the lowerend of the tube extension 62. i

These springs in conjunction with the dogs 58 f and 59 effect therequisite snap action of the re- Shoulder enversing valve, as will bedescribed.

The operation of the pump will now be explained, having particularreference to Figures 2, 3, Il, and 5 in which the arrows indicate therelative directional ow of the pump operating `uid and the lproductionliquid.

In the position o'f the parts as shown in Figurges 3, 4, and 5 and infull lines in Figure 2 the pump is at the end of its upstroke just priorto reversal of the valve i6 to the dotted line position of Figure 2.Operating fluid is supplied under pressure from the surface pump 1 downthrough the well tubing 4 entering the pump through the connectingbushing 16 above the head Iii.- The fluid pressure maintains the checkvalves 13 closed. The uid passes down through the passages |4 to theinlet chamber I3 and as the valve I6 is closed against its lower seat |1lthe fluid rises through the bore 20 and radial bores 2| to the passages22, traveling down channels 29 of the head 36, see Figures 4 and 11, A

entering the casing below the head and filling it around the cylinder'3land the working barrel 48.

From the lower portion of the pump casing interior the uid enters thecylinder 3| through the ports 32 beneath the piston 33 'forcing thepiston upwardly and thereby lii'ting with the piston the upper and lowerplungers 34 and 35.

During the up-stroke, it should be explained,

'the valve I8 is latched in its closed position against the seat I1 byreason or the Iact that the dogs 53' are projected into the reducedportion 98 of the valve stem extension over the vshoulder the valve stemabutment 55. The cam slots 53 permit the cam to ride up over the shanks98 of thendogs 58 without influencing the dogs until the bottom riser 54of the cam engages -behind the outer ends of the dogs and retracts themradially, releasing them from engagement with the valve stem shoulder51. This release is timed to occur at the end of the pump upstroke, and

immediately upon release of the dogs the comv pressed spring 54 expandsand snaps the valve stem upwardly, forcing the reversing valve I6against its upper seat 55.

When this snap action reversal of the valve I6v At the same time thecross-head 18 rises in the bore 1I to engage the detent 33 against itslower face to hold the valves in their respective posi- During upwardmovement of the piston 33 the operating fluid in the cylinder above thepiston is elevated through the passages 35 of the head 30 and throughthe annular passage 31 between the tube 49 and the tube 21 upwardly overthe outer face of the housing 11 and through the passage 38 of the head23 into the chamber 39. From chamber 39 the iluid passes downaround thevalve stem 85 into the loutlet chamber 81 and through the dischargeports I9 into the well casing 2 where it mingles with the risingproduction liquid and is carried. to the well head.

The production liquid entering the pump through the standing valve 45Aiills the plungers 34'and 35 and is elevated with these plungers, thetraveling valve `44 being closed on upstroke. As the plunger 34 rises onthe pump upstroke the production liquid beneath the abutvment 52, whichis a partition extending entirely across the bore of the tube 53, isdisplaced from the passage 95 between the plunger and tube 4,discharging from the pump through the outlet ports I2 into` the wellcasing immediately above the packerC 82, whereupon it is lifted to thewell head as the .pump continues to operate and is discharged togetherwithA the operating iluid through the lead oil' 5.

The reversal of valve I8 at the 'end o f the upstroke immediately eectscommencement of theN :downstroke without interruption to the -ow of.

- the reduced portion 91 of the valve stem extension 55 to engagebeneath the stem extension 1 takes place the upper valve I8 is openedand i the lower valve is closed against its seat 4I.

. the space 95 beneath the partition 52 into the bore 50 of .the head 38and out through the disshoulder 51 and thus latch the valve stem in itsreversed'position.

The ilow of operating iluid on the downstroke of the pump is the reverseof 'its`ilow on the upstroke. On the downstroke the iluid. entering thechamber I3 in the head I5 is shifted by the closing of valve I8 againstits upper seat so that it passes down through the bore 88 in the head 23to chamber 39 thence down through the passages 38 to the annular passage31 and down to the head 3U. It passes down through the passages 38 inthe head 30 and issues against the upper face of the piston 33, forcingthe piston down in the cylinder 3l and carrying down the plungers 34 and35. A y

Operating fluid on the discharge side of the piston is expelled from thecylinder 3|. through the ports 32 and rises through the outer channels29 of the head 39,' up through the annular passage 28 between thetubular member 21 and the pump casing 28, through the passages 24 of thehead 23 to the annular space 25 at the upper end of this head. From the`space 25 the fluid passes up through the passages 22 in the head I5,through the radial bores 2l to the axial bore 20 and up through the openupper valve I8 to the outlet chamber 83 from which it discharges intothe well casing through the ports I I. l

On the down stroke of the piston the standing valve 46 is closed and thetraveling valve 44 is held open whereby the production liquid trapped inthe working'barrel is forced into the lower plunger 35 to displace itscontained production into the upper plunger 34 from which the productiontherein is in turn displaced through the radially slotted head 5I on itsupper end into charge ports I2 to the interior'of the well casing. Asthe cross-sectional -area of the lower plunger is greater than that ofthe upper the capacity of the lower plunger exceeds that ofthe upper. Inconsequence, during the entire down stroke of the upper plunger thevolume of production discharged from its upper end will exceed thevolume of its capacity, and the rate and Irom the bore 58 oi the head39, see Figure of production discharge from the ports I2 will beapproximately equal and continuous through both strokes of the pump.

on the lower end of the movable tube 53 and pulls down this tube tocompress the spring 68, Figure 3, against the valve stem abutment 55. Asthe plunger moves to the limit of its downstroke the extension 52,moving down with the tube 53, will move the top riser 55 of the cam |88into engagement with the dogs 59 whereby to retract these dogs radiallyfrom their holding engagement with the valve stem' shoulder 51.

Immediately on release of the dogs 53 the exconstruction of the pump andthe capacity of vthe well tubing 4. In a pump of the character disclosedherein the .ratio between the volume of operating uid usedand the volumeof `the 'As the upper plunger 34 moves down its head .5I contacts thestop bushing 81, see Figure 4,

the net pressure of theoperating fluid and the static pressure in thewell. In consequence, a pump designed to use low pressure operatingliuid will require va greater volume, of the uid for a given volume ofproduction than 'will a' pump which is designed to use high pressureopthe unbalanced valve areas will tend to raise the valves from their,seats, permitting small leaks erating uid. Conversely, proportioning thepisthe friction loss, or drop inpressure, of the fluid in passingthrough the tubing is an important factor in determining the overalleiiiciency of the pump. As the drop in pressure due to the frictionvaries as the square of the velocity, it is evident that decreasing thevolume of operating fluid required will decrease the velocity, and inconsequence reduce the friction loss. In the perfomance of a givenamount of work, if the volume is decreased the pressure must beincreased.

In the practice of the invention the relations between the pressures andVolumes of the operating fluid and the production will be determinedbefore the pump is built, and the areas of the piston and plungers willbe proportioned accordingly. i

As a rule, the cross sectional area of the lower plunger will beapproximately twice that of the upper, although in cases whereconsiderable production pressure exists this ratio of areas may bevaried depending upon the intensity of the production pressure. ByVarying .the cross sec-A tional areas of the plungers to correspond withthe production pressure and the static head in the well, the pressure ofthe operating uid on the up and down strokes may be equalized, therebyeliminating load fluctuations on the surface pump.

Also, the relation between the eiective area of the piston and theplungers may be varied for different installations. In deep wells, wherethe static pressure against which the pump must operate is high, thearea of the plungers will be small with relation to the .effective areaof the piston. In shallow wells the plunger areas can be made muchlarger with relation to the piston area.

A feature to be noted in the valve and seat arrangement is that theintake valve I6 is of larger diameter than the exhaust valves I8 and 40.The object of thisconstruction may be exy plained by reference to Figure2, this description having particular reference to the valve positionsshown by full lines. vIn this view, the valves IB and I8 are seated onthe seats I'I and I9 respectively, with the high pressure working iiuidbetween the two valves. As the area of the Valve I6 is greater than thearea of the valve I8, it

.is clear that the pressure of the working uid will hold the valvesagainst ltheir seats, the force with which they are held in thisposition depending upon the difference inthe valve areas.

While the pump is being run into the well casing, the casing is 'full ofliquid, or partly so, and the tubing 4 is dry. Thus, as the pumpislowered into the well a high static pressure will be encounteredacting inwardly through the exhaust ports I0 and II. The static pressurein the well as the pump is being lowered will then act: on the largeIarea of the valve I6 and the smaller area of whichever of the `dischargevalves between the valves and their seats. Since the uid in the wellcasing invariably contains sand or other abrasive materialsfth valveseats and valves might be damaged by these leaks. In order to eliminatethis objectionable condition the ball checks 13 are-provided in the plug'I2 which is inserted in the head I5 in the top of the bore 1I. Thecross-head 10 has a seriesof holes 14 therethroughestablishingcommunication with the discharge ports II. Any pressureexceeding the'pressure inthe tubing 4 will be relieved through the portsII, cross-head 10 and check valves 13 into the tubing 4 and thepossibility of cutting the valves and seats during lowering of the pumpwill be eliminated.

Having thus described the invention, what is claimed is:

1. A fluid pressure operable pump for wells, comprising a cylindricalcasing adapted to be supported von the lower end of a well tubing, ahead on the upper end of said casing, said head f having an axial bore,a valve stem guided in said leading from the bore at the other side ofthe valve to the other side of the piston, liquid elevating meanscarried by said piston and operable axially within said casing, andmeans carried by said liquid elevating means for engaging said valvestem to reverse said valve at each reciprocal limit of the piston.

2. In a iluid pressure operable well pump, a casing, a liquid liftmember reciprocable therein, uid pressure actuated means in the casingfor reciprocating said lift member, means for supplying an operatingfluid under pressure to the'casing, a reversible valve in saidcasinglfor reversing the direction of ow of the operating fluid through thecasing to the lift member reciprocating means. astem on said valve, atubular member slidable axially over said stem and having an abutment,an abutment on said stem, an expansion spring coiled on the valve stemwithin said tubular member and compressible between said abutments inone direction of movement of Athe tubular member, means on said liftmember engageable with said tubular member to move the latter duringreciprocation of the lift member, a latch carried by a stationary partof the pump and normally holding the valve stem against movement, andlatch releasing cam means carried by said tubular member for releasingthe latch at the reciprocalflimits of said lift member. Y

3.l A fluid pressure operable pump for wells, comprising in combinationwith a well casing, a cylindrical pumpv casing disposed therein, acylindrical head at the upper end of the pump casing, a cylindrical headat the bottom thereof, a cylinder disposed axially in the lower portionof the pump casing, a piston reciprocable in the cylinder, a hollowtubular upper plunger'carried by said piston and reciprocable throughthe I8 or 40 is seated. The pressure acting thus on 75 upper end of thecylinder, a larger hollow tubu- -on said valve stem at the lower endthereof, a

tubular member slidably engaging over both said valve stem extension andthe upper plunger, a rresilient operating connection between the stemextension and tubular member, cooperating means on said tubular memberand upper plunger for reciprocating said tubular member in accordancewith reciprocationof the plunger, whereby through said resilientconnection the valve stem extension is shifted to eiect a reversal ofsaid valve at each reciprocal limit of the piston, and a dischargepassage for liquid issuing from said upper plunger, said passage openingat the exterior of the pump casing into the well casing. l

4. The structure of claim 3. including a packing ring disposed betweensaid pump casing and well casing immediately vbelow the liquid dischargeopening through the pump casing.

5. The structure of claim 3, a barrel attached to the bottom head of thepump casing in axial alignment with said lower plunger, and a standingvalvein saidrbarrel. e

6. In a Viiuid pressure operable well pump havl ing a reversible fluidpressure inlet control valve,

. and a liquid lift member reciprocable by reversed application of uidpressure controlled by the valve; a bushing carried by a stationaryvpart of the pump, said valve having a stem extension slidable throughsaid bushing and having an abutment thereon adjacent the bushing, springpressed detents carried by said bushing and normally urged into the pathof said stem abutment to restrain said stem and valve against axialmovement, a tubular member slidable 'axially over the stem extension,means on said lift member for reciprocatingsaid tubular member, saidtubular member being longitudinally slotted to ride freely over saiddetents during a portion of its reciprocating travel, and cam risers onsaid member engageable with said detents iiuid passage leading from saidupper conduit to one end of said fluid motor, said lower conduit .fromthe inlet chamber communicating with the lower discharge chamber, ailuid passage leading from said lower conduit to the other end of saidiiuid motor, a stem on said reversing valve disposed through both saidconduits, an upper valve on said stem closing of! the upper dischargechiamber when the reversing valve closes oif the lower conduit, and alower valve on said stem closing oilr said lower discharge chamber whenthe reversing valve closes oil the upper conduit, and means operable onthe valve stem to reverse the position of said valve at each limit ofthe reciprocal movement of said liquid lift means.

8. In a uid pressure operable well pump, a casing, liquid lift means,reciprocable therein, means for supplying an operating uid underpressure to the casing for reciprocating the lift means, a uid pressuredistributing head assembly on said casing and having an inlet chamberfor theA operating fluid, an upper discharge chamber above the inletchamber and open to the casing exterior, a lower discharge chamber belowthe inlet chamber and open to the casing exterior, said head assemblyhaving an axial bore connecting all said chambers, a pressure fluidconduit leading from the upper part oi said bore between the inlet andupper discharge chamber to a workingelement of the lift means, apressure uid conduit leading from the lower :part of the bore betweenthe inlet and lower discharge chambers to a working element of the liftmeans, a control valve in the inlet chamber I movable in one directionto close off the lower part of the bore, a stem' on said valve anddisposed through both parts of said bore, al upper valve on said stemclosing oi the upper discharge chamber, a lower valve on said stemclosing off the lower discharge chamber when the cdntrol valve closes oithe upper part of said bore, and means for shifting the valve stem tofor distributing uid for the operation of said to retract same at thereciprocal limits of travel of the tubular member.

7. In a fluid pressure operable well pump, a

I casing, liquid lift means including a iluid motor reciprocabletherein, means for supplying an operating iiuid under pressure to themotor to operate said lift means, a iluid pressure distributor head onsaid casing for distributing uid for the operation of said lift meansand having an interior inlet chamber for the operating fluid, adistribution conduit leading from the upper part of said chamber, adistribution conduit leading from the bottom part of the chamber, areversing valve in said chamber operable to one position to close theupper conduitand Ito another position to close the lower conduit, ,achamber above said inlet chamber and having a discharge outlet to thecasing exterior, a' chamber below said inlet chamber and having adischarge outlet to the casing exterior,- said upper conduit from theinlet chamber communicating with said upper discharge chamber, a

lift means andv having an interior inlet chainber for the operatingfluid, a distribution copduit leading from the upper part of saidchamber, a fluid passage between said upper conduit and one end of thefluid motor, a distribution conduit leading from the bottom part 0Isa'id chamber, a fluid passage between said bottm conduit and theotherend of the fluid motor, a' I reversing` valve in said chamber'operable to one position to close the upper conduit and to anotherposition to close the lower conduit, a chamber above said inlet chamberand having a discharge outlet to the casing exterior, a chamber belowsaid inlet chamber and having a discharge outlet to the casing exterior,said upper conduit from the inlet chamber communicating with said upperdischarge chamber, said lower -4conduit from the inlet chambercommunicating valve on said stem closing voli! said lower dis\ chargechamberwhen the reversing valve closes` off the upper conduit, and saidreversing valve being of a greater effective area than either the upperor lower valve.

10. In a iiuid pressure operable well pump, a

' below the inlet chamber andl open to the casing,v

exterionsaid head assembly having an axial bore connecting all saidchambers, a pressure nid. conduit leading from said bore between theIinletv chamber and the upper discharge chamberto a working element ofthe lift means, a pressure fluid conduit leading from said bore be.-tween the inlet chamber and lower discharge chamber to a working elementof the lift means, a disc shaped control valve in the inlet chambermovable in one direction to closeoi the bore below the inlet valve andextending above and below the Vahle axially in said bore, said controlvalve being movable in azi-opposite direction to close of; the bore-above the inlet chamber, an ,upper disc valve arranged onA said stem toclose H the upper discharge chamber when the control valve closesthebore below the inlet chamber, a lower disc valve arranged onsaidfstem to close off the lower 'discharge chamber when the controlvalve closes the bore above the inletv chamber,

and the area of said control valve being geater than the area oi theupper valve and greater thevalve disc faces retains the'valves tightlyclosed when moved to theirlimits.

chamber, a sternv on said controll in a wall of the casing, and meansoperable by the plunger for supplying a. fluid pressure mediumalternately to opposite sides of the piston to reciprocate the plunger.

12. In a rluid pressure operable well pump, a casing, liquid lift meansincluding a iluid motor reciprocable therein,` means for supplying anoperating fluid under pressure to the motor to operate said lift means,a fluid pressure distributor head on said casing for distributing fluidfor the operation of said lift means and having an interior chamber forthe operating iiuicl, a distribution conduit leading from the upper partof' said chamber, a fluid passage be,- tween said? upper conduit and oneend oi?v the fluid,` motor, a distribution conduit leading from thebottom part of said chamber, a fluid passage between said bottom conduitand the other end than the area of the lower:` valve, whereby thediierences in pressure o! operating fluid against ofv the,A uid motor, areversing valve in said chamber operable to one position to close theupperv conduit andto another position to close the tower conduit, a.chamber below said inlet chamber and. having adischarge outlet to thecasing, exterior, said lower conduit from the inlet chambercommunicating with the lower discharge chamber, a chamber24 above saidinlet chamber and having a discharge outlet to the Ycasing exterior,said upper conduit from the inlet chamber communicating with said upperdischarge chamber, said head being bored above said upper chamber incontinuation thereof, a stem on said reversing valve disposed throughlall of said conduits, chambers and bore, an upper valve on 'said st emclosing off the. upper discharge chamber when the reversing valve closesoff the lower conduit, a lower valve on said stem closing oil said lowerdischarge chamber when the reversing valve closes of! the upper conduit,

means operable on the valve stem to reverse the position of said valvesat ,each limit of the reciprocal movement of cross-head on said stem andguided in the bore above said upper chamber, and detent means'in a wallof said bore engaging said cross-head to latch same inu eitherreciprocal limit position oi.' the stem.

13. The structure of claim 12, and pressure relier valve meansopening'from said bore to the exterior of said head above thecross-head.

CHARLES J. WOLFF.

said liquid lift means, a.

